Movable equipment for electro-magnetically controlled devices



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April 29, 1958 J. L. REUTTER 2,832,919

MOVABLE EQUIPMENT FOR ELECTRO-MAGNETICALLY CONTROLLED DEVICES Filed J me 12, 1953 2 Sheets-Sheet 1 .24 I 1 j .11 5 a? 35 M LF i as L .3

INVENTOK JEAN 'L. REUTTER ATTK April 29, 1958 J. L. REUTTER 2,832,919

MOVABLE EQUIPMENT FOR ELECTRO-MAGNETICALLY CONTROLLED DEVICES Filed June 1953 2 Sheets-Sheet 2 Pie. 4.

Zgggg umuuuuu! 4/ WV d /l A mu INVENTOK JEAN L- REUTTER United States Patent 6 MOVABLE EQUIPMENT FOR ELECTRO-MAGNETI- CALLY CONTROLLED DEVICES Jean Leon Reutter, Vesenaz, Geneva, Switzerland Application June 12, 1953, Serial No. 361,321

Claims priority, application France March 10, 1953 Claims. (Cl. 317-188) This invention relates to movable equipment for electro-magnetically controlled devices having a shuttle forming a magnetic core adapted for reciprocating movement.

The shuttles or magnetic cores employed in devices having a reciprocating movement and controlled by electro-magnetic means, such as refrigeration compressors operating on this principle, generally consist of one piece which is preferably cast and machined. However, by reason of the difficulty frequently encountered in cooling such devices, the heat generated by the parasitic currents produced are difiicult to dissipate, which sometimes results in harmful overheating in the device, whereby the eificiency thereof is considerably reduced. Another disadvantage resides in that the fluid situated on each side of the core is compressed in the chambers in which it moves. Since the elasticity of the compressed fluid varies with the temperature, it is necessary to provide transfer passages between the chambers in which the core moves, with the result that the manufacture of the apparatus is complicated, while the problem is not entirely solved, since the compressed fluids have appreciable and variable viscosities. This is the case in particular with the cooling fluids employed in refrigerating apparatus.

An object of the present invention is to obviate these disadvantages.

Broadly in accordance with the invention, movable equipment for electro-magnetically controlled devices having a shuttle forming a magnetic core adapted for reciprocating movement comprises an elongated element of substantially cylindrical form, the centre portion of which forms or supports a portion of larger diameter which in turn supports on its periphery a tubular element on which are mounted bundles of laminations disposed in the longitudinal direction and insulated from one another so that the' magnetic field which is closed through these laminations does not generate parisitic currents and that portion of larger diameter, in which apertures of large cross-section are formed, does not compress, during the movement of the shuttle, the fluid situated on either side of, the two lateral sides but permits the said fluid to passfreely from one side to the other.

For a better understanding of the invention and to show how the same may be carried into eifect, reference will now be made to the accompanying drawings, in which:

Figure 1 is a diagrammatic longitudinal sectional elevation of an electro-magnetically controlled compressor mounted for reciprocating movement and provided with a shuttle according to the present invention.

Figure 2 is a sectional elevation on a larger scale of the magnetic core of the compressor diagrammatically illustrated in Figure 1.

Figure 3 is a section along the line III-III of Figure 2.

Figure 4 is a sectional elevation on a smaller scale, similar to Figure 2, illustrating a modified construction.

2,832,919 Ce Patented Apr. 29, 1958 Figure 5 is a sectional elevation of a second modification, and

Figure 6 is a sectional elevation of a third modification.

The compressor shown in Figure 1 comprises a cylindrical jacket 1 closed at each of its ends by fluid-tight casings 2 and 3 in which compression cylinders 7, 8 are mounted by means of plates 5, 6. The jacket 1, which preferably consists of a metal of high electrical resistivity, is engaged in apertures formed for this purpose in a magnetic circuit 9, which may have, for example, the form shown in the drawing.

Electro-magnetic windings 10 are disposed between the branches 11, 12 of the magnetic circuit on either side of two permanent magnets 13, 14 situated as shown in Figure l. The windings 10 are fed with alternating current by means of conductors 15, the ends of which are connected to the contact studs of a bipolar switch 16 by which they are connected, when desired, to the current lead-in conductors 17.

The interior of the jacket 1 serves to house a shuttle 18 forming a magnetic core arranged to move reciprocally when the electro-magnetic windings 10 are energized. Springs 19, 20 disposed between the two ends of the shuttle 18 and the inner ends of the casings 2 and 3 impart a pre-determined vibration frequency to the said shuttle. The shuttle 18 is connected by rods 21, 22 to pistons 23, 24 sliding in the compression cylinders 7, 8 respectively.

Figures 2 and 3 show in detail the particular construction of the shuttle 18, which is intended to control the pistons 23, 24 when it is moved under the action of the alternating magnetic field produced by the windings 10 and closed through the magnetic circuit 9. The said shuttle 13 comprises a core 25 consisting of an elongated metal element which isof circular section in the constructional form illustrated. The core 25 forms or supports at its centre part a cylindrical element 26 having longitudinal holes 27 of large cross-section formed therein. An annular groove 28 formed in the periphery of the element 26 is provided to secure the centre portion 29 of a cylindrical tube 30 which is mounted on the element 26. Ribs 31 and 32 are then formed in the tube 30 on either side of the element 26 in order that the said tube may be more conveniently keyed to prevent it from moving in relation to the said element 26. The tube 30 is intended to serve as a support for bundles of laminations 33 disposed around its entire periphery as shown in Figure 3.

The laminations 33 are provided at each end with lugs 34 over which there are fitted the binding elements 35 serving to maintain the laminations against the tube 30.

The terminal edges 36 of the tube 30 are then bent over at a right angle in order to maintain the inturned edges 37 of the binding elements 35, which thus completely fitfrom moving longitudinally in relation to the tube 30.

The laminations 33, which are preferably coated with a layer of insulation consisting of varnish or a plastic material, are shaped as shown in Figure 3, so that their curvature compensates for the differences in the length of the circumferences extending through their upper and lower ends.

To facilitate the positioning of the bundles of laminations 33, the tube 30 previously mounted on the body 26 fast with the core 25 is disposed in a concentric tube, the internal diameter of which is equal to the external diameter of the said tube 30 plus twice the height of the laminations 33. After the assembly, the said second tube is withdrawn and the external periphery of the laminations and the lateral edges thereof are machines, as shown in dash-dotted lines and designated by the reference 38 in Figures 2 and 3. Threaded holes 39 are formed in the ends of the core 25 to permit screwing engagement with the ends of the rods 21, 22 connecting the shuttle to the pistons 23, 24.

The magnetic field produced by the windings It? is closed by the shuttle is and the parasitic currents, such as Foucault currents, are reduced to a minimum by reason of the laminated structure of the said shuttle, whereby the electrical losses and consequently the heating of the compressor are considerably reduced. When the compressor is in operation that is to say when the shuttle 18 is moving within the jacket 1. under the action of the alternating magnetic field produced by the windings 10, the fluid contained in the chambers 40 defined by the inner ends of the casings 2, 3 and the sides of the shuttle, passes from one to the other through the large apertures 27 formed in the element 26, so that the said fluid is never compressed and the action thereof can thus be neglected. In the modified construction illustrated in Figure 4, the core 25 of the shuttle comprises a portion of larger diamete the top of which is knurled as shown at 41. This portion serves as a bearing surface for a toric plate 42 which is, for example, moulded under pressure simultaneously with the tube 30 serving to support the bundles of laminations 33. Both the plate 42 and the tube 39 may consist of a plastic material such as a. polyamide, or any other suitable material having good qualities of resistance and lightness, for example, aluminum alloys or the like. The mould into which the material for the production of the plates 42 and the tube 30 is introduced is so fashioned that a ring of material 43 covers the lugs 34 formed by the laminations 39, which are disposed in the mould before the filling material is introduced. The longitudinal apertures 27 are formed, for example, directly by moulding or after the manufacture of the shuttle.

Figure shows another modification in which the core 25 is only knurled at its centre portion 44. Cut away portions 45 are formed at each of the two ends of the said core, which is placed in a mould in the manner already described, in order that a jacket 46 forming the outer covering may be deposited on the said core at the same time that the plate 42 and the tube 36 are formed, in the manner hereinbefore described. The cut-away portions 45 and the knurled portion 44 prevent any movement of the core 25 in relation to the material forming the shuttle.

In Figure 6, the whole shuttle is produced from east material, the screw-threads 39 and the holes 27 being formed in the moulding.

The invention is not limited to the embodiments illustrated and described in detail by way of example, because modifications may be made therein without departing from the scope thereof. In particular, the shuttle hereinbefore described may be employed in various other devices, such as vibrators, operating in accordance with the same principle as the compressor hereinbefore described by way of example. Similarly, the laminations 33 may be disposed radially, but in this case it is found advantageous for their section to be of trapezoidal form, in order to compensate for the difference in the length of 4 the circumferences extending through their upper and lower ends.

I claim:

1. A magnetic armature or shuttle for reciprocation in a magnetic circuit for oscillating compressors and pumps comprising an elongated core, a perforated partition element forming an integral part of said core substantially at its middle portion, a tubular member carried by said perforated element and extending concentrically with said core and elongated magnetic laminations secured at the periphery of said tubular element.

2. A magnetic armature or shuttle for reciprocation in a magnetic circuit comprising an elongated core, a perforated round partition secured at the middle portion of said core, a tubular element fitted and secured to said round partition, said tubular element having outwardly bent marginal edges, elongated laminations of magnetic metal disposed substantially along radii around said tubular element, lugs formed at each end of said laminations to come in abutment with said outwardly bent marginal edges of said tubular element and rings fitted on said lugs to secure said laminations and said tubular element.

3. A magnetic armature or shuttle for reciprocation in a magnetic circuit comprising an elongated core, said core having a perforated middle portion of larger diameter than the end portions and provided with a peripheral groove, a tube fitted on said middle portion, said tube having ribs engaging said peripheral groove and the lateral edges of said middle portion, said tube having terminal outwardly bent portions, laminations extending lengthwise on said tube and binding elements fitted at the ends of said laminations to maintain them on said tube between said terminal outwardly bent portions.

4. A magnetic armature for reciprocation in a magnetic circuit, the improvement in said shuttle comprising a metallic core having a middle knurled portion, a toric plate of non-magnetic material surrounding said knurled portion, said toric plate having longitudinal holes, a nonmetallic tube secured to said toric plate concentrically to the core and electrically insulated laminations peripherally disposed on said tube, said laminations having lugs and said tube having rings covering said lugs to secure together said tube and said laminations.

5. A magnetic armature or shuttle for reciprocation in a magnetic circuit for oscillating compressors and pumps comprising an elongated core, a perforated partition element integral with said core located substantially at the middle portion thereof, a tubular nonmagnetic member mounted on said partition element concentrically to said core, and magnetic laminations electrically insulated one with respect to the other extending from said tubular member and secured thereto, said laminations being curved in vertical sectionso that they bear one against the other at their outer and inner ends.

References Cited in the file of this patent UNITED STATES PATENTS 

